1. Field of the Invention
This invention pertains to self-sealing tanks and more particularly to such tanks which retain their self-sealing ability when penetrated by large or tumbling projectiles.
2. Description of the Prior Art
Prior attempts to construct self-sealing tanks usually have employed a tank wall which includes a flowable sealant. This type of tank wall usually includes a sealant which swells when it comes in contact with either air, or the contained fluid, or a separate swelling agent. In these types of self-sealing tanks, a bullet or other projectile penetrating the tank wall will cause the included sealant to flow into the bullet hole until the flow has been choked off and a dry seal obtained. Examples of such structure are taught in U.S. Pat. No. 3,664,904 and U.S. Pat. No. 3,801,425, both to Richard L. Cook. Other tank constructions utilize elastomeric foam or foaming compositions which, when exposed to the contained fluid, foam or swell to close the hole.
Known types of self-sealing containers are most efficient when called upon to seal small diameter holes. As the diameter of the hole caused by the projectile increases, the ability of the tank self-sealing feature to close the hole diminishes. This is especially true when the hole is cored. The flowing sealant begins to close the hole but is swept through the hole by the rapidly escaping fluid, thus making sealing of large holes impossible with most conventional self-sealing tank constructions.